diff --git a/cashu/core/b_dhke.py b/cashu/core/b_dhke.py
index 80735ef..3bf6490 100644
--- a/cashu/core/b_dhke.py
+++ b/cashu/core/b_dhke.py
@@ -35,7 +35,7 @@ import hashlib
 from secp256k1 import PrivateKey, PublicKey
 
 
-def hash_to_curve(message: bytes):
+def hash_to_curve(message: bytes) -> PublicKey:
     """Generates a point from the message hash and checks if the point lies on the curve.
     If it does not, it tries computing a new point from the hash."""
     point = None
@@ -49,28 +49,30 @@ def hash_to_curve(message: bytes):
     return point
 
 
-def step1_alice(secret_msg: str, blinding_factor: bytes = None):
-    Y = hash_to_curve(secret_msg.encode("utf-8"))
+def step1_alice(
+    secret_msg: str, blinding_factor: bytes = None
+) -> tuple[PublicKey, PrivateKey]:
+    Y: PublicKey = hash_to_curve(secret_msg.encode("utf-8"))
     if blinding_factor:
         r = PrivateKey(privkey=blinding_factor, raw=True)
     else:
         r = PrivateKey()
-    B_ = Y + r.pubkey
+    B_: PublicKey = Y + r.pubkey
     return B_, r
 
 
-def step2_bob(B_, a):
-    C_ = B_.mult(a)
+def step2_bob(B_: PublicKey, a: PrivateKey) -> PublicKey:
+    C_: PublicKey = B_.mult(a)
     return C_
 
 
-def step3_alice(C_, r, A):
-    C = C_ - A.mult(r)
+def step3_alice(C_: PublicKey, r: PrivateKey, A: PublicKey) -> PublicKey:
+    C: PublicKey = C_ - A.mult(r)
     return C
 
 
-def verify(a, C, secret_msg):
-    Y = hash_to_curve(secret_msg.encode("utf-8"))
+def verify(a: PrivateKey, C: PublicKey, secret_msg: str) -> bool:
+    Y: PublicKey = hash_to_curve(secret_msg.encode("utf-8"))
     return C == Y.mult(a)
 
 
diff --git a/cashu/lightning/lnbits.py b/cashu/lightning/lnbits.py
index 7dbf54a..f7e2db3 100644
--- a/cashu/lightning/lnbits.py
+++ b/cashu/lightning/lnbits.py
@@ -30,6 +30,7 @@ class LNbitsWallet(Wallet):
     async def status(self) -> StatusResponse:
         try:
             r = self.s.get(url=f"{self.endpoint}/api/v1/wallet", timeout=15)
+            r.raise_for_status()
         except Exception as exc:
             return StatusResponse(
                 f"Failed to connect to {self.endpoint} due to: {exc}", 0
@@ -61,6 +62,7 @@ class LNbitsWallet(Wallet):
         data["memo"] = memo or ""
         try:
             r = self.s.post(url=f"{self.endpoint}/api/v1/payments", json=data)
+            r.raise_for_status()
         except:
             return InvoiceResponse(False, None, None, r.json()["detail"])
         ok, checking_id, payment_request, error_message = (
@@ -82,6 +84,7 @@ class LNbitsWallet(Wallet):
                 json={"out": True, "bolt11": bolt11},
                 timeout=None,
             )
+            r.raise_for_status()
         except:
             error_message = r.json()["detail"]
             return PaymentResponse(None, None, None, None, error_message)
@@ -112,6 +115,7 @@ class LNbitsWallet(Wallet):
                 url=f"{self.endpoint}/api/v1/payments/{checking_id}",
                 headers=self.key,
             )
+            r.raise_for_status()
         except:
             return PaymentStatus(None)
         if r.json().get("detail"):
@@ -123,6 +127,7 @@ class LNbitsWallet(Wallet):
             r = self.s.get(
                 url=f"{self.endpoint}/api/v1/payments/{checking_id}", headers=self.key
             )
+            r.raise_for_status()
         except:
             return PaymentStatus(None)
         data = r.json()
diff --git a/cashu/mint/ledger.py b/cashu/mint/ledger.py
index 8cff05d..5d3d4cd 100644
--- a/cashu/mint/ledger.py
+++ b/cashu/mint/ledger.py
@@ -129,15 +129,6 @@ class Ledger:
             ]
 
         C = PublicKey(bytes.fromhex(proof.C), raw=True)
-
-        # backwards compatibility with old hash_to_curve < 0.4.0
-        try:
-            ret = legacy.verify_pre_0_3_3(private_key_amount, C, proof.secret)
-            if ret:
-                return ret
-        except:
-            pass
-
         return b_dhke.verify(private_key_amount, C, proof.secret)
 
     def _verify_script(self, idx: int, proof: Proof):